Automatically dump stack trace in case of internal Maven error

Details

Description

This output isn't really helpful:

[ERROR] Internal error: java.lang.NullPointerException -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/InternalErrorException

We know by the nature of this exception that we need more information to analyze the issue (where did the nested exception occur within the core?), i.e. the stack trace is pretty much required. As such, we should automatically dump it to the console as if -e was given. This is not only more convenient for the user as it saves him from re-running the build but also ensures we capture valuable data for an error that might only show up occasionally.